Bottle closure having a wood top

ABSTRACT

A closure for a bottle includes a wooden element, a first polymer layer, and a second polymer layer. The wooden element has a shaft portion and a head portion. The head portion is wider than the shaft portion. The shaft portion extends in an axial direction. The first polymer layer is molded onto the shaft portion, and has an outer surface having at least one annular discontinuity. The second polymer layer is disposed over the first polymer layer, and is configured to be received by a bottle in the axial direction.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/015,827, filed Aug. 30, 2013, which is incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention relates generally to bottle closures.

BACKGROUND OF THE INVENTION

Bottle closures for consumable liquids, for example, olive oil, syrup,spirits and wine, have historically been metal and/or cork material.Cork is made from bark of certain trees, for example, the Cork Oak. Corkhas qualities particularly suited to storing liquids in bottles becauseit features impermeability and a certain level of compressibility thatallows for both a tight closure and removability. In contrast to bark,wood fibers do not have sufficient compressibility.

Due to extensive use, however, cork supplies are limited, therebydriving up price. Moreover, cork closures carry with them the risk of ataint that can be passed into the liquid. For example, it has beenestimated that as many as seven percent of wine bottles have some levelof “corking”, or taint imparted by the cork.

By far, the most popular closure for mass-produced bottled liquids isthe metal “screw top cap”. Metal screw tops are formed of a metal skirtand plastic sealing layer. Screw tops extend over the outside of thebottle, as opposed to corks that are inserted into the bottle neck.While screw top caps are not susceptible to taint, screw top caps lackaesthetic appeal, which is particularly disadvantageous forhigher-valued products such as fine spirits, fine wine, and higher endolive oil and maple syrup.

In other cases, it has been found that certain polymers can be used forbottle closures that behave in a manner more similar to cork. Polymerclosures can have similar compressibility. However, polymer closuressimilarly suffer from a lack of aesthetics associated with fine spirits,wine and other products. Furthermore, polymer closures are given to“creep”, which deforms the closure over time and can lead to failure.

Some attempts have been made to combine certain materials with thepolymer closure to take advantage of the mechanical properties of thepolymer while improving the aesthetics. In one example, a closureincludes a wooden head or cork head portion glued to a thermoplasticpolymer portion. The thermoplastic polymer portion inserts into thebottle, while the wooden head remains outside the bottle and provides agripping portion for extraction. The drawback of this design is that theglue joints often fail, causing separation of the polymer sealingmaterial from the wood.

What is needed is a bottle closure that has sealing qualities comparableto cork, while having a suitable aesthetic human interface.

SUMMARY OF THE INVENTION

The present invention addresses the above state need, as well as others,by providing a bottle closure having a wooden core (and head), with apolymer molded onto the wooden core. The wooden core provides structuralintegrity and the wooden head provides convenient and aesthetic removalinterface.

In a first embodiment, a closure for a bottle includes a wooden element,a first polymer layer, and a second polymer layer. The wooden elementhas a shaft portion and a head portion. The head portion is wider thanthe shaft portion. The shaft portion extends in an axial direction. Thefirst polymer layer is molded onto the shaft portion, and has an outersurface having at least one annular discontinuity. The second polymerlayer is disposed over the first polymer layer, and is configured to bereceived by a bottle in the axial direction.

In another embodiment, a closure for a bottle includes a stopper portionand a wooden head portion. The stopper portion has a first axial lengthand a first width, and is configured to be received at least in partwithin a bottle in the axial direction. The stopper portion includes awooden inner part and a polymer outer part, the wooden inner part havinga second axial length that is less than 75% of the first axial length.The wooden head portion has a second width that exceeds the first width.The first axial length and the second axial length are defined from abottom of the wooden head portion.

The above-described features and advantages, as well as others, willbecome more readily apparent to those of ordinary skill in the art byreference to the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows perspective view of a bottle closure according to at leastone embodiment of the invention;

FIG. 2 shows a side plan view of the bottle closure of FIG. 1;

FIG. 3 shows a bottom plan view of the bottle closure of FIG. 1;

FIG. 4 shows a side plan view of a wood portion of the bottle closure ofFIG. 1;

FIG. 5 shows a side cutaway view of a first embodiment of the bottleclosure of FIG. 1;

FIG. 6 shows a side cutaway view of a second embodiment of the bottleclosure of FIG. 1;

FIG. 7 shows a side cutaway view of an alternative embodiment of abottle closure;

FIG. 8 shows a side plan view of a wood portion of the bottle closure ofFIG. 7; and

FIG. 9 shows a perspective view of the wood portion and a first polymerlayer of the bottle closure of FIG. 7.

DETAILED DESCRIPTION

FIG. 1 shows perspective view of a bottle closure 100 according to atleast one embodiment of the invention. FIGS. 2 and 3 show, respectively,side and bottom plan views of the bottle closure. Reference is made toFIGS. 1, 2, and 3 simultaneously. The bottle closure 100 includes astopper portion 102 and a head portion 104, and includes a substantiallycylindrical outer wall 126. The stopper portion 102 has an axial lengthand a width in the radial direction. The width of the stopper portion102 is sized such that the stopper portion 102 can be tightly receivedat least in part within the neck of a bottle containing spirits, wine,olive oil, maple syrup, mineral water, and other liquids, not shown. Thestopper portion 102, when received with the bottle, is slightlycompressed to form a liquid tight fit within the bottle. The headportion 104 has a width that exceeds the width of the stopper portion102, and is not received with the neck of a standard bottle, but israther configured to abut a top axial-facing edge of the bottle, as isconventional.

With reference to FIG. 4, in addition to FIGS. 1-3, the stopper portion102 includes a wooden inner part 106 and a polymer outer part 108. FIG.4 shows a side plan view of the wooden inner part 106 and the headportion 104. The wooden inner part 106 and the head portion 104 areintegrally formed of a single, turned piece of wood, referred to hear asthe wood part 109. FIGS. 5 and 6, discussed further below, showdifferent embodiments of the polymer outer part 108. In general,however, the polymer outer part 108 defines a substantially cylindricalouter surface 126 that is configured to engage the inner surface of theneck of a bottle.

As discussed above, the head portion 104 and the wooden inner part 106are integrally formed from a single piece of wood, as opposed to barkmaterial used for corks. Suitable wood materials include, but are notlimited to beech, birch, maple, oak, bamboo. The wooden inner part 106is in the form of a shaft having a first end 120 at the intersection ofthe head portion 104, and a distal or second end 122.

The wooden inner part or shaft 106 defines a generally cylindricalstructure having at least one discontinuity. The discontinuity providesan area where the polymer outer part 108 can contract onto and “grip”the wooden inner part 106 during the molding process. In thisembodiment, the discontinuities include two annular grooves 110, 112.The annular groove 110 includes a radially extending upper surface 114,a radially extending lower surface 116 and an axial inner surface 118.The annular groove 112 may suitably have the same structure. The annulargrooves 110, 112 are spaced apart on the wooden inner part 106 by anaxial distance that is roughly equivalent to the axial width of theaxial inner surface 118. Similarly, the annular grooves 110, 112 arespaced apart from the two axial ends 120, 122 of the wooden innerpart/shaft 106.

One feature of the annular grooves 110, 112 is the provision of anundercut, preferably in a radial plane. For example, in the annulargroove 110, the upper surface 114 and the lower surface 116 formundercuts. As will be discussed below in further detail, when thepolymer outer part 108 is molded onto the wooden inner part 106, thepolymer engages the undercuts and contracts, thereby strengthening theretention force of the polymer outer part 108 on the wooden shaft 106.Accordingly, it will be appreciated that suitable undercuts may takeother forms, such as detents, bores, and the like. One advantage of acontinuous annular groove such as the grooves 110, 112 is that it allowsthe undercuts to be formed in a rotating wood working fixture, such as alathe.

It is also preferably that the grain 111 of the wood part 109 beoriented in the axial direction, or in other words, substantiallyparallel to the angle of insertion into the bottle. Such orientationadvantageously provides maximum bending strength on the core, andoptimum fiber orientation for product insertion and extraction forces.

Accordingly, to construct the wood part 109, a blank wood piece isloaded onto a lathe or other rotating machine such that the grain of thewood blank is parallel to the axis of rotation. Suitable machiningmethods are used on the rotating wood blank to form the wood part 109 asshown in FIG. 4. It will also be appreciated that the machining methodstypically causes random chipping-out, or random hollow spots 113, whichcreate their own discontinuities that aid in the bonding of the polymermaterial to the wood shaft 106.

In this embodiment, the wooden shaft 106 also includes an annular moldmating structure 124 at the first end 120, adjacent to an engaging theunderside of the head portion 104. The annular mold mating structure 124in this embodiment defines an inclined annular surface similar to afillet structure. The annular mold mating structure 124 is configured toprovide an interface for the molding fixture, not shown. The moldingfixture can clamp down and slightly deform the mating structure 124 toform a tight contact ring between the mold and the shaft, therebyinhibiting or preventing undesirable leaks or flashing of the polymermaterial beyond its intended position.

As discussed above, the polymer outer part 108 defines a substantiallycylindrical outer wall 126 that engages the inner wall of a bottle. In afirst embodiment discussed below in connection with FIG. 5, the polymerouter part 108 consists of a single, molded polymer that is molded overthe wooden shaft 106. In a second embodiment discussed below inconnection with FIG. 6, the polymer outer part 108 consists of at leasttwo molded polymers having different physical characteristics.

Referring to FIG. 5, shown is a side cutaway view of the firstembodiment of the bottle closure 100 of FIG. 1 having a single, moldedpolymer structure. Like reference numbers will be used to illustratelike features from FIGS. 1 to 4. The polymer outer layer 108 is a singlematerial molded onto the shaft portion to form a substantiallycylindrical outer surface 126 configured to be received by a bottle inthe axial direction. To this end, the mold, not shown, comprises anegative of the outer cylindrical surface 126 of the polymer outer layer108. The mold is clamped against the annular mold mating structure 124to prevent polymer material from flashing out to the underside 128 ofthe head portion 104.

It can be seen that the polymer outer layer 108 fills the annulargrooves 110, 112, and forms a layer over the second end 122 of thewooden shaft 106. In the cross-section shown in FIG. 5, the polymerouter layer 108 makes up between 25% and 75% of the width of the stopperportion 102. The resulting thickness of the wood shaft 106 providesstrengthening characteristics not present in the polymer material.

When the polymer cures, it contracts (shrinks), forming axial clampingforces on the undercuts (e.g. radially extending surfaces 114, 116) andon the second end 122 of the wooden shaft 106. The polymer preferablyshrinks at least one or two percent. Such clamping forces help securethe structure and prevent failure or separation. In addition, the random“pitting” or hollow spots 113 on the shaft 106 formed during themanufacturing process provides places for the polymer to lock duringpost-molding shrinkage to enhance the mechanical bond. This method ofmechanical shrinkage bonding provides superior torque resistance betweenthe wood shaft 106 and the polymer shaft 108. Such torque resistance isparticularly advantageous because this type of closure is often rotated,relative to the bottle, upon insertion and extraction. Also, theporosity and pits in the wood (imperfections) provide excellentasymmetric, random grip points for the shrink bond of the moldedpolymer.

Accordingly, the material of the polymer outer portion 108 should bechosen such that it is soft or elastic enough to allow for bottleinsertion and extraction, while providing a tight liquid seal, and havesufficient hardness to secure itself about the wooden shaft 106. To thisend, the polymer may suitably be one or more of propylene, thermoplasticelastomer, a blowing agent (endothermic), or SEBS. One suitable blend isthe TPE and blowing agent described in U.S. Pat. No. 5,710,184.

FIG. 6 shows a second embodiment of the bottle closure wherein thepolymer outer layer 108 includes a first polymer layer 130 and a secondpolymer layer 132. The first polymer layer 130 preferably includes ahard polymer layer 130 molded onto the wooden shaft 106 similar tomethod described above in connection with FIG. 5. A second polymer layer132 is molded onto the first polymer layer 130, and forms the outercylindrical wall 126 of the polymer outer layer 108. The molding processcreates a cohesive bond between the second polymer layer 132 and thefirst polymer layer 130.

The first polymer layer 130 has a greater hardness, and may have greatershrinkage, than the second polymer layer 132, thereby allowing forstrong coupling to the wood shaft 106. The second polymer layer 132 maybe softer, and even softer than the polymer material of the embodimentof FIG. 1, because the second polymer layer 132 has a cohesive bond tothe first polymer layer 130. The combination of the layers 130 and 132make for a strong closure device, with enhanced flexibility forinsertion into and retraction out of the bottle. The wooden shaft 106,as with the embodiment of FIG. 5, provides strength and preventsdegradation of the structural soundness of the polymer over time, whichcan be an issue with all polymer closures.

In one preferred embodiment the first polymer layer 130 may includepolypropylene and the second polymer layer 132 may include thermoplasticelastomer (TPE). However, either or both of these materials may bealtered.

FIGS. 7, 8 and 9 illustrate an alternative embodiment of the bottleclosure of FIG. 6. FIG. 7 shows a side cutaway view of a bottle closure200 according to this alternative embodiment. The bottle closure 200 maysuitably have an external appearance that is substantially identical tothat of the closure 100, and thus has a plan view substantiallyidentical that shown in FIG. 2. However, the internal structures of thebottle closure 200 differ from those of the bottle closure 100, as willbecome readily apparent upon review of FIGS. 7, 8 and 9.

Referring now to FIG. 7, the alternative bottle closure 200 includes astopper portion 202 and a head portion 204, and includes a substantiallycylindrical outer wall 226. The stopper portion 202 has an axial lengthand a width (OD of the outer wall 226) which may suitably the same asthat of the stopper portion 102 of the closure 100. In other words, thewidth of the stopper portion 202 is sized to be tightly received atleast in part within the neck of a bottle containing spirits, wine,olive oil, maple syrup, mineral water, and other liquids, not shown. Aswith the stopper portion 102, the stopper portion 202 is slightlycompressed when inserted to form a liquid tight fit within the bottle.The head portion 204 has a width that exceeds the width of the stopperportion 202, and is not received with the neck of a standard bottle, butis rather configured to abut a top axial-facing edge of the bottle, asis conventional.

The stopper portion 202 includes a wooden inner part 206 and a polymerouter part 208, the polymer outer part including a first polymer layer230 and a second polymer layer 232. Further details regarding thepolymer outer part 208 are discussed further below in connection withFIG. 9.

FIG. 8 shows a side plan view of the wooden inner part 206 and the headportion 204 apart from the polymer outer part 208. The wooden inner part206 and the head portion 204 are integrally formed of a single, turnedpiece of wood, referred to hear as the wood part 209. Similar to thewood part 109, the head portion 204 and the wooden inner part 206 areintegrally formed from a single piece of wood, as opposed to barkmaterial used for corks. Suitable wood materials include, but are notlimited to beech, birch, maple, oak, bamboo. The wooden inner part 206is in the form of a shaft having a first end 220 at the intersection ofthe head portion 204, and a distal or second end 222.

The wooden inner part or shaft 206 defines a generally cylindricalstructure having at least one discontinuity. The discontinuity providesan area where the polymer outer part 208 can contract onto and “grip”the wooden inner part 206 during the molding process. In thisembodiment, the discontinuities include two annular grooves 210, 212.Thus, the shaft 206 is similar to the shaft 106 shown in FIG. 4.However, in contrast to the shaft 106 of FIG. 4, the shaft 206 has anaxial length L₂ that is less than 75%, and preferably less than 50% ofthe overall axial length L₁ of the stopper portion 202. (See FIG. 7).This allows for a reduction in the amount of wood that is used, which isreplaced by lower cost polymer materials of the polymer outer part 208.As with the shaft 106 discussed above in connection with FIG. 4,discontinuities in the shaft 206 can take other forms. Moreover, theshaft 206 need not have a general cylindrical shape at all. The shaft206 may suitably have other features as those of the shaft 106, and maybe formed in the same way.

Moreover, it will be appreciated that the reduced length shaft 206 mayreadily be employed in the embodiments of the closure 100 discussedabove in connection with FIGS. 1 to 6. Conversely, the polymer outerpart 208 of FIG. 7 may be implemented with the longer shaft 106 of FIG.4. Nevertheless, the reduced length of the shaft 206 is particularlyadvantageous because it can provide material cost reduction.

As discussed above in connection with FIG. 7, the polymer outer part 208includes a first polymer layer 230 and a second polymer layer 232. Aswith first polymer layer 130 of the embodiment of FIG. 6, the firstpolymer layer 230 preferably includes a hard polymer layer 230 moldedonto the wooden shaft 206 similar to method described above inconnection with FIG. 5. A second polymer layer 232 is molded onto thefirst polymer layer 230, and forms the outer cylindrical wall 226 of thepolymer outer layer 208. The molding process creates a cohesive bondbetween the second polymer layer 232 and the first polymer layer 230.The materials of the first polymer layer 230 and the second polymerlayer 232 may be the same (and/or have the same characteristics) asthose of the respective first polymer layer 130 and second polymer layer132 of FIG. 6.

In contrast to the embodiment of FIG. 6, however, the first polymerlayer 230 includes at least one annular discontinuity in its outersurface. FIG. 9 shows a perspective view of the first polymer layer 230molded onto the shaft 206 (not visible in FIG. 9) of the wooden part 209apart from the second polymer layer 232. As shown in FIG. 9 the firstpolymer layer 230 includes an inner shaft 240 and a plurality of ribs242 extending radially outward from the inner shaft 240 at differentannular locations. Each of the ribs 242 has a length that extendsaxially along at least the entire axial length the inner shaft 240. Eachof the ribs 242 has a radial height that extends radially outward fromthe inner shaft 240. The ribs 242 are spaced apart such that portions ofthe inner shaft 240 separate adjacent ribs. The ribs 242 and the shaft240 thereby define an outer surface 244 with annular discontinuities. Byannular discontinuities, it is meant that the annular outer surface isnot a continuous curve.

The discontinuities formed by the ribs 242 create torsion that assistsin retaining the strong bond between the first polymer layer 230 and thesecond polymer layer 232.

It will be appreciated that the ribs 242 may be replaced with otherstructure on the shaft 240 that form such discontinuities. In thisembodiment, the inner shaft 240 is roughly bullet shaped, have asubstantially cylindrical body 250 extending from the head portion 204and terminating in a rounded conical point 252. The ribs 242 extendalong the entire length of the inner shaft 240, including the length ofthe rounded conical point 252, as shown in FIG. 9.

It will be appreciated that the above-described embodiments are merelyillustrative, and that those of ordinary skill in the art may readilydevise their own implementations and modifications that incorporate theprinciples of the present invention and fall within the spirit and scopethereof. By way of example, it will be appreciated that the dimensionsof the closures 100, 200 may be altered to suit the bottle neck design.In addition, the length of the stopper portions 102, 202 and width ofthe head portion 104, 204 may be altered without departing from theprinciples of the embodiments described herein.

In addition, it will be appreciated that the discontinuities used tostrengthen the bond between the wood shafts 106, 206 and the polymer outlayer(s) may take different forms. While the embodiment described hereinrelies on annular grooves and hollow spots chipped out during machining,at least some embodiments may rely solely on discontinuities formed bychipped-out hollow spots formed during the machining of the shaft. Inaddition, other forms of chipping or forming of overhangs the shaft maybe employed. Nevertheless, the use of at least two annular grooves hasbeen shown to provide particularly reliable connection between the woodshafts 106, 206 and the polymer outer parts 108, 208.

What is claimed is:
 1. A closure for a bottle, comprising a stopperportion having a first axial length and a first width, the stopperportion configured to be received at least in part within a bottle inthe axial direction, the stopper portion comprising a wooden inner partand a polymer outer part, the wooden inner part having a second axiallength that is less than 75% of the first axial length; and a woodenhead portion having a second width that exceeds the first width; andwherein the first axial length and the second axial length are definedfrom a bottom of the wooden head portion.
 2. The closure of claim 1,wherein said wooden head portion and said wooden inner part areintegrally formed from a single piece of wood.
 3. The closure of claim2, wherein the wooden inner part comprises a shaft, said shaftcomprising a cylindrical structure having at least one discontinuity. 4.The closure of claim 3, wherein said shaft includes at least one annulargroove defining the at least one discontinuity.
 5. The closure of claim4, wherein the shaft includes at least two annular grooves defining theat least one discontinuity.
 6. The closure of claim 4, wherein thepolymer defines a substantially cylindrical outer surface.
 7. Theclosure of claim 1, wherein the polymer outer part further comprises afirst polymer layer and a second polymer layer, the first polymer layerdisposed between the second polymer layer and the wood inner part. 8.The closure of claim 7, wherein the first polymer layer includes anouter surface and at least one annular discontinuity in the outersurface.
 9. The closure of claim 8, wherein the first polymer layer parthas a different hardness than the second polymer layer.
 10. A closurefor a bottle, comprising a wooden element having a shaft portion and ahead portion, the head portion having a width greater than the shaftportion, the shaft portion extending in an axial direction; a firstpolymer layer molded onto the shaft portion, the first polymer layerhaving an outer surface having at least one annular discontinuity; and asecond polymer layer disposed over the first polymer layer, the secondpolymer layer configured to be received by a bottle in the axialdirection.
 11. The closure of claim 10, wherein the first polymer layerincludes an inner shaft, and wherein the at least one annulardiscontinuity comprises a plurality of ribs extending radially outwardfrom the shaft.
 12. The closure of claim 11, wherein the each of theplurality of ribs extends axially along said inner shaft.
 13. Theclosure of claim 12, wherein the head has a width that exceeds a widthof an opening in the bottle.
 14. The closure of claim 13, wherein theshaft portion comprises a cylindrical structure having at least oneaxial discontinuity.
 15. The closure of claim 14, wherein said shaftincludes at least one annular groove defining the at least one axialdiscontinuity.
 16. The closure of claim 15, wherein the annular groovedefines at least one undercut, the undercut having a surface extendingsubstantially in a radial direction normal to the axial direction. 17.The closure of claim 10, wherein the first polymer layer part has adifferent hardness than the second polymer layer.
 18. A closure for abottle, comprising a wooden element having a shaft portion and a headportion, the head portion having a width greater than the shaft portion,the shaft portion extending in an axial direction, the shaft includingat least two annular grooves; a first polymer layer molded onto theshaft portion; and a second polymer layer molded onto the first polymerlayer and configured to be received by a bottle in the axial direction.19. The closure of claim 18, wherein the first polymer layer has adifferent hardness than the second polymer layer.
 20. The closure ofclaim 19, wherein the first polymer layer includes an inner shaft and aplurality of ribs extending radially outward from the shaft.